n. 1 A specific radio frequency or band of frequencies used for transmitting television. 2 A station or broadcaster using the band.
n. a television station and its programs; "a satellite TV channel"; "surfing through the channels"; "they offer more than one hundred channels" [syn: channel, TV channel]
A television channel is a physical or virtual channel over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video ( VSB) and 59.75 MHz for analog audio ( FM), or 55.31 MHz for digital ATSC ( 8VSB). Channels may be shared by many different television stations or cable-distributed channels depending on the location and service provider.
Depending on the multinational bandplan for a given region, analog television channels are typically 6, 7, or 8 MHz in bandwidth, and therefore television channel frequencies vary as well. Channel numbering is also different. Digital television channels are the same as their analog predecessors for legacy reasons, however through multiplexing, each physical radio frequency (RF) channel can carry several digital subchannels. On satellites, each transponder normally carries one channel, however multiple small, independent channels can be on one transponder, with some loss of bandwidth due to the need for guard bands between unrelated transmissions. ISDB, used in Japan and Brazil, has a similar segmented mode.
Preventing interference between over-the-air channels in the same area is accomplished by skipping at least one channel between two analog stations' frequency allocations. (Where channel numbers are sequential, frequencies are not contiguous, such as channel 6 to 7 skip from VHF low to high band, and channel 13 to 14 jump to UHF.) On cable TV, it is possible to use adjacent channels only because they are all at the same power, something which could only be done over the air if the two stations were transmitted at the same power and height from the same location. For digital TV, selectivity is inherently better, therefore channels adjacent (either to analog or digital stations) can be used even in the same area.
Usage examples of "television channel".
She yawned and desperately turned the television channel to rock music videos.
The television channel abruptly switched to a commercial extolling the virtues of an underarm deodorant.
Picking up the television channel control he flicked it on, watched flatly for a few minutes and then switched it off.
The old movies still ran on one television channel, but the others were snow.
He had monitored every television channel, had shielded the device against radio frequencies, and the ghosts remained.
Apparently a controversial film had been shown on the NABS television channel in the United States which had created a furore across the continent.
But once Simon was finished with it, it would be the most spoken place name on every television channel, every radio station and every newspaper on the planet.
And for another, he stood upright, very casual as if doing nothing more enervating than contemplating a change of television channel in his living room.